1. Field of the Invention
This invention relates to hydrotherapy jets.
2. Description of the Related Art
Various hydrotherapy jets have been developed for use in spas, hot tubs, pools and bath tubs that discharge a stream of water, which can be aerated through a variety of discharge nozzles. The designs provide different flow characteristics that result in different massage affects being experienced by the body. Such jets have been found to produce a pleasing massaging effect for many users, and have become quite popular. In the design of single or multi-user spas or tubs, it is common to use a variety of different jet nozzles to provide a variety of different massaging effects.
Early jets simply discharged a steam of warm water along the longitudinal axis of the jet body, with later jets providing aeration of the water stream. Since then, numerous jets have been developed in which the direction of the stream can be adjusted. For example, U.S. Pat. No. 5,269,029 to Spears et al. (assigned to the same assignee as the present invention) discloses a jet that provides an off axis stream of water and has an axial push/pull mechanism used to control the flow of water. The mechanism can also be rotated to rotate the stream of water around the jet axis, providing directional control over the stream.
Jets have also been developed having a rotating outlet or eyeball that automatically rotates in response to the water flowing through the outlet. See Waterway Plastics Inc., “1999 Product Catalog,” Page 4, including Part Nos 210-6120 and 210-6510. The jet produces a water jet that passes through the outlet, and the outlet can be adjusted off the jet's longitudinal axis to provide a turning moment in the eyeball in response to the jet flow.
U.S. Pat. No. 6,178,570 to Denst et al. (assigned to the same assignee as the present invention) discloses a jet having a rotating eyeball with one or more discharge outlets that can be adjusted to vary the direction of the outlet flow stream as well as the direction and speed of the eyeball's rotation. A high-pressure water stream flows through the outlets and, depending upon the orientation of the outlets, the eyeball can rotate clockwise or counterclockwise at different speeds.
U.S. Pat. No. 5,920,925, to Dongo (assigned to the same assignee as the present invention) discloses a jet having a rotating eyeball and a diverter cap formed with a number of bore holes positioned at a common radius from the center of the cap. The jet produces a high pressure water jet that flows through the eyeball, causing it to rotate at a high speed and discharge the jet in a circular pattern that impinges on the bore holes. Together, the rotational speed and the bore hole design produce the sensation of a number of simultaneously pulsating water jets that are directed into the spa.
One disadvantage of these rotating jets is that they rely on internal bearings to allow the outlet or eyeball to rotate. This approach is effective in allowing free rotation, but the bearings are relatively expensive and add complexity in design and manufacturing of the jets. Also, calcium can build up on the bearings from water and over time the build-up can prevent the free rotation of the outlet.
U.S. Pat. No. 5,226,601 to Hinojosa Jr. et al. (assigned to the same assignee as the present invention) describes a jet with an alternative mechanism for allowing an outlet or eyeball to rotate. A bridge stretches across the front face of the jet and includes a rearward-directed cup mounted at the center of the bridge along the jets longitudinal axis. The cup holds a bushing, which in turn holds a pin. The pin extends into a corresponding opening in the front end of the eyeball to hold it in place. The eyeball rotates in response to a steam of water passing through it by having its outlet angled to the jet's longitudinal axis.
One disadvantage of this arrangement is that the bridge adds to the cost and complexity of the jet's design and manufacture. Also, the jet usually includes one or more internal nozzles that form the stream of water flowing through the jet into a venturi. This allows air to be entrained into the stream of water to provide a aerated stream. However, the vacuum effect of the venturi tends to pull the outlet toward the back of the jet. As a result, the pin/bushing combination must hold the eyeball within the cup against the pull of the venturi vacuum, which makes the bridge type jet even more difficult to design and manufacture. Also, the bridge interferes with the stream of the water from the rotating outlet as it passes under the arms of the bridge. This results in multiple interruptions in the flow of water, which may be undesirable in some circumstances.
U.S. Pat. No. 5,291,621 to Mathis describes a spa jet assembly having a pin shaft that extends along the entire length of the jet. It is held in a circular opening in the rear most surhce of the jet by a pop rivet. The pin passes through a jet head with the jet head being held by a pop rivet, so that there are opposing pop rivets on the pin.
On disadvantage of this jet arrangement is that if the rear of the jet is used as the water inlet, a significant portion of the inlet is blocked by a rear axial surface that supports the circular opening. This restricts the amount of water that can pass into the jet and creates turbulence in the water that does pass. If the rear of the jet is not used as a water inlet, such as in jets with side water inlets, the rivet and pin passing through the rear of the jet, which creates an opening through which water can leak.